The aim of the present program is to enhance the understanding of the pathogenesis and treatment of atherosclerosis by using experimental animal models and cells grown in tissue culture. In the current year it is planned to: 1) characterize further the biochemical pathology and pathophysiology of atherosclerotic and hypertensive disease especially involving the cerebral and coronary vessels of the cynomolgus monkey; 2) investigate the physical chemistry of the plasma lipoproteins and lipids contained in the atherosclerotic lesions; 3) to assess the effect of cholesterol feeding on the lysysl oxidase activity and crosslinkage content of elastin and collagen of the arterial wall of rabbits and monkeys; 4) clarify the biosynthesis of connective tissue proteins, acid mucopolysaccharides and proteoglycans in intact arteries and isolated smooth muscle cells; 5) investigate the role of platelet arachidonic acid metabolism in the pathogenesis of atherosclerosis; and 6) complete studies on the effects of aspirin on experimentally induced atherosclerosis in the cynomolgus monkey.